The researchers write in the journal current biology On January 13, 2022, they discovered a huge breeding colony of ice fish in southern Antarctica, the Weddell Sea. They estimate that the colony covers at least 240 square kilometers and has about 60 million active nests. The unprecedented colony represents a fish biomass of over 60,000 tons (or more than 135 million pounds).
“The most important finding of ours is the pure existence of such a vast ice fish farming colony,” says Autun Purser of the Alfred Wegener Institute in Bremerhaven, Germany. “A few dozen nests have been spotted elsewhere in Antarctica, but this find is an order of magnitude larger.”
Purser and colleagues made the discovery while surveying the Filchner ice shelf using the Ocean Floor Observation and Bathymetry System (OFOBS). “This is basically a large, one-ton hauling device that we got behind the RV Polarstern icebreaker at speeds of one to four kilometers per hour,” he explains. “We’re pulling this about 1.5 to 2.5 meters above the sea floor, and we’re recording video and acoustic bathymetry data.”
The researchers were particularly interested in this area of the sea floor because they knew that it involved a two-degree rise in the water
“A very large number of Weddell seals spend most of their time in close proximity to fish nests,” Purser says. “We know this from historical tracking data and recent tracking data from our sea voyage. Nests are exactly where the warm waters flow. These facts may be coincidental, and more work is needed, but recorded seal data shows that seals are indeed diving deep into the nests.” fish, so it might be a good idea to eat those fish.”
The results revealed a globally unique ecosystem, according to the researchers. It also provides support for the establishment of a regional marine protected area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources.
The researchers have now deployed two camera systems to monitor the ice fish’s nests until the research vessel returns. We hope that images taken several times a day will yield new insights into the workings of this newly discovered ecosystem. Purser says he has plans to return in April 2022 to conduct seafloor surveys in areas of the northeastern Weddell Sea.
For more information on this research, see ‘Amazing Find’ in Antarctica: Massive Ice Fish Breeding Colony with 60 Million Nests.
Reference: “Antarctic ice fish breeding colony discovered” by Autun Purser, Laura Hehemann, Lilian Boehringer, Sandra Tippenhauer, Mia Wege, Horst Bornemann, Santiago E.A. Pineda-Metz, Clara M. Flintrop, Florian Koch, Hartmut H. Hellmer and Patricia Burckhardt Holm, Marcus Janot, Elaine Werner, Barbara Glemser, Gina Balaguer, Andreas Rogge, Moritz Holtables and Frank Winshofer, January 13, 2022, current biology.
DOI: 10.1016 / j.cub.2021.12.022
This work was supported by AWI, the H2020 INTAros project, and the PACES Program of the Helmholtz Association.